1. Field of the Invention
This invention relates to improvements in information display devices of the kind in which a plurality of shutter members are selectively movable to close or to leave unobstructed an individual aperture in a two-dimensional array of apertures, so as to form the characters or other symbols to be displayed.
2. Description of the Prior Art
In known devices of this kind, such as are described in my U.S. Pat. No. 3,562,938 the shutter members are discs movable in the plane of the array by rotation about an axis perpendicular to the plane of the array, rolling upon the floors of the respective cells. This movement is produced by magnetic fields acting upon the shutter member. In some embodiments of this known arrangement the disadvantage arises that there is very considerable friction between the shutter member and that wall of the cell against which it must slide, because the shutter member is urged against the cell wall by the magnetic field serving to produce its movement.